Sainsbury's enjoyed its busiest trading week ever in the run-up to Christmas, helping like-for-like sales in its latest quarter climb by 0.2%.

Chief executive Justin King said the 14 weeks to January 4 had been a "very tough sales environment" but the supermarket managed to maintain its record of growth - after it was forecast to fall after 35 successive periods of expansion.

Mr King said the seven days prior to Christmas was the group's busiest ever trading week, with more than 28 million transactions.

Mr King said: "This quarter has been characterised by a very tough sales environment throughout October and November, with customers saving up in order to treat their families over the Christmas period.

"However, we saw strong sales in the key period over Christmas."

He described the period as "our best Christmas ever".

Analysts had pencilled in a like-for-like sales fall for the quarter as major supermarkets continue to feel the squeeze from discounters Aldi and Lidl as well as higher end grocers such as Waitrose - which reported booming seasonal sales today.

However, while there will be relief at the 0.2% sales increase, it is a marked slowdown compared to the 2% hike in the second quarter and the 0.9% rise for the same period last year.

Today's trading update from Sainsbury's also revealed that customers redeemed £120 million worth of points under its Nectar card loyalty scheme, to help with the cost of their festive shop - a 9% increase on last year.

Mr King warned that as with last year, shoppers were expected to spend cautiously in the months following Christmas to rebalance household finances amid a background of continued economic uncertainty for families.

The group said its busiest pre-Christmas trading day was December 23, with the busiest hour of that day seeing customers spend £17 million. Its store in Stanway, Essex, became the first Sainsbury's to record £1 million sales in one day.

Sainsbury's Taste the Difference brand saw sales up 10% over the quarter, with 100,000 fresh turkeys and turkey crowns sold under the premium label.

The supermarket's Christmas ordering service saw more than 100,000 orders, up 24% year-on-year.

Sainsbury's said its convenience store business was growing at nearly 18%, with Christmas Eve seeing record £7 million sales.

Online groceries grew by more than 10% in the quarter, as the store revamped its website. The division saw the strongest ever sales day on December 22, reaching more than £5 million.

Sainsbury's added 555,000 square feet of new space over the period, including six supermarkets, four extensions and 19 convenience stores.